Definitions of the levels of evidence (I-V) and grades of recommendation (A-C, I) and are provided at the end of the "Major Recommendations" field.
Recommendation 1.1
The physician should obtain an accurate patient history (Level V, Grade C).
Recommendation 2.1
The physician should perform a physical examination of the patient that may include:
- Personal characteristics (Level V, Grade C)
- Performing a sensory examination (Level V, Grade C)
- Performing manual muscle testing of the upper extremity (Level V, Grade C)
- Performing provocative tests (Level V, Grade C), and/or
- Performing discriminatory tests for alternative diagnoses (Level V, Grade C)
Recommendation 3.1a
The physician may obtain electrodiagnostic tests to differentiate among diagnoses. (Level V, Grade C)
Recommendation 3.1b
The physician may obtain electrodiagnostic tests in the presence of thenar atrophy and/or persistent numbness (Level V, Grade C).
Recommendation 3.1c
The physician should obtain electrodiagnostic tests if clinical and/or provocative tests are positive and surgical management is being considered (Level II and III, Grade B)
Recommendation 3.2
If the physician orders electrodiagnostic tests, the testing protocol should follow the American Academy of Neurology/American Association of Neuromuscular and Electrodiagnostic Medicine/American Academy of Physical Medicine and Rehabilitation (AAN/AANEM/AAPMR) guidelines for diagnosis of carpal tunnel syndrome (CTS) (Level IV and V, Grade C).
Recommendation 3.3
The physician should not routinely evaluate patients suspected of having carpal tunnel syndrome with new technology, such as magnetic resonance imaging (MRI), computerized axial tomography (CAT), and pressure specified sensorimotor devices (PSSD) in the wrist and hand. (Level V, Grade C).
Please note that Recommendation 3.3 is not based on a systematic literature review. An additional abbreviated review was completed following the face to face meeting of the Work Group on February 24, 2007.
Definitions:
Levels of Evidence for Primary Research Question1
Types of Studies |
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Therapeutic Studies
Investigating the results of treatment
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Prognostic Studies
Investigating the effects of a patient characteristic on the outcome of disease
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Diagnostic Studies
Investigating a diagnostic test
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Economic and Decision Analyses
Developing an economic or decision model
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Level I |
- High quality randomized trial with statistically significant difference or no statistically significant difference but narrow confidence intervals
- Systematic review2 of Level I randomized controlled trials (RCTs) (and study results were homogenous3)
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- High quality prospective study4 (all patients were enrolled at the same point in their disease with >80% follow-up of enrolled patients)
- Systematic review2 of Level I studies
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- Testing of previously developed diagnostic criteria on consecutive patients (with universally applied reference "gold" standard)
- Systematic review2 of Level I studies
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- Sensible costs and alternatives; values obtained from many studies; with multiway sensitivity analyses
- Systematic review2 of Level I studies
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Level II |
- Lesser quality RCT (e.g., <80% follow-up, no blinding, or improper randomization)
- Prospective4 comparative study5
- Systematic review2 of Level II studies or Level I studies with inconsistent results
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- Retrospective study6
- Untreated controls from an RCT
- Lesser quality prospective study (e.g., patients enrolled at different points in their disease or <80% follow-up)
- Systematic review2 of Level II studies
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- Development of diagnostic criteria on consecutive patients (with universally applied reference "gold" standard)
- Systematic review2 of Level II studies
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- Sensible costs and alternatives; values obtained from limited studies; with multiway sensitivity analyses
- Systematic review2 of Level II studies
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Level III |
- Case control study7
- Retrospective6 comparative study5
- Systematic review2 of Level III studies
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- Study of nonconsecutive patients; without consistently applied reference "gold" standard
- Systematic review2 of Level III studies
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- Analyses based on limited alternatives and costs; and poor estimates
- Systematic review2 of Level III studies
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Level IV |
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- Case-control study
- Poor reference standard
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- Analyses with no sensitivity analyses
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Level V |
Expert opinion |
Expert opinion |
Expert opinion |
Expert opinion |
1 A complete assessment of quality of individual studies requires critical appraisal of all aspects of the study design.
2 A combination of results from two or more prior studies.
3 Studies provided consistent results.
4 Study was started before the first patient enrolled.
5 Patients treated one way (e.g., cemented hip arthroplasty) compared with a group of patients treated in another way (e.g., uncemented hip arthroplasty) at the same institution.
6 The study was started after the first patient enrolled.
7 Patients identified for the study based on their outcome, called "cases"; e.g., failed total hip arthroplasty, are compared to those who did not have outcome, called "controls"; e.g., successful total hip arthroplasty.
8 Patients treated one way with no comparison group of patients treated in another way.
Recommendation Grades
A: Good evidence (Level I Studies with consistent finding) for or against recommending intervention.
B: Fair evidence (Level II or III Studies with consistent findings) for or against recommending intervention.
C: Poor-quality evidence (Level IV or V) for or against recommending intervention.
I: There is insufficient or conflicting evidence not allowing a recommendation for or against intervention.
Grading Recommendations Specific to the CTS Guideline: When studies employ readers who were not blinded to each other and/or to the symptoms of the patient, we downgraded the quality of a study by one level of evidence (i.e., unblinded studies introduce the possibility of bias).
Relevant Issues:
The Committee recognized the following language in constructing the recommendations: Strong Recommendation (Must), Recommendation (Should), Option (May), or no recommendation. These definitions help clarify the intent of the Work Group by reflecting the assessment of the importance of adherence to the recommendation based on the grade level of the recommendation.